1. Field of the Invention
The present invention relates to binary coded magnetic devices such as computer memories and shift registers.
2. Description of the Prior Art
Magnetic bubble domain devices of the prior art typically represent binary information by means of the existence or lack of a bubble at a specific location and time. Such devices typically feature chips made of epitaxially grown rare-earth ferrimagnetic garnet layers overcoated with ferromagnetic film drive patterns. The ferromagnetic film drive patterns may be made of, for example, the nickel-iron alloy sold as Permalloy, or other suitable soft magnetic materials. The drive patterns generally provide means for generating, moving and annihilating magnetic bubbles in the adjacent garnet layer. Under the influence of a high frequency rotating magnetic field the magnetic bubbles move under the attraction and repulsion of the alternating magnetic poles induced in the drive patterns. Detection of a magnetic bubble may be achieved by a number of different techniques known to those skilled in the art, of which are Hall effect sensors, magnetoresistance sensors and magneto-optic sensors.